# US 2017/0283294 A1 · Glass inlet tube environmental control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0283294 A1 - Document ID: US20170283294A1 - Status: Published application - Kind: A1 - Application number: 15/509,240 - Filed: 2015-09-25 - Published: 2017-10-05 - Earliest claimed: 2014-09-29 - Assignees: Corning Incorporated - Applicants: Corning Incorporated - Inventors: Robert Delia; Shawn Rachelle Markham; Brandon Thomas Sternquist; Nathan Tyler Qualls - Web page: https://patentgrep.com/patent/US20170283294A1 ## CPC - C03B 5/1675: {Platinum group metals} - C03B 5/16: Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces - C03B 5/43: Use of materials for furnace walls, e.g. fire-bricks - C03B 7/02: Forehearths, i.e. feeder channels - C03B 17/064: {by the overflow downdraw fusion process; Isopipes therefor} - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES ## Abstract A system and method are described herein for controlling an environment around an inlet tube in the glass manufacturing system. More specifically, the system and method control a level of hydrogen within a humid gas mixture that flows over an exterior of the inlet tube to effectively suppress the formation of undesirable gaseous inclusions in molten glass that flows through the inlet tube. ## Claims ### Claim 1 A system for controlling an environment around an inlet tube in a glass manufacturing system, wherein the inlet tube comprises an inlet body, an input opening, and an output opening, said system comprising: an electrical heating unit encompassing at least a portion of the inlet tube and having a gas inlet unit and a gas outlet unit each passing therethrough; a first seal proximate the input opening and intermediate an exterior of the inlet body and the electrical heating unit; a second seal proximate the output opening and intermediate the exterior of the inlet body and the electrical heating unit; a refractory tower encompassing the electrical heating unit and having the gas inlet unit and the gas outlet unit each passing therethrough; and, a control system that directs a humid gas mixture into the gas inlet unit such that the humid gas mixture flows over the inlet body and exits the refractory tower and the electrical heating unit via the gas outlet unit. ### Claim 2 (depends on 1) The system of claim 1, wherein said inlet tube includes a metal selected from platinum, platinum-containing metals including platinum-rhodium, platinum-iridium and combinations thereof, or refractory metals including palladium, rhenium, ruthenium, and osmium, or alloys thereof. ### Claim 3 (depends on 1) The system of claim 1, wherein the control system is configured to control a level of hydrogen within the humid gas mixture so that a partial pressure is maintained at or greater than a level defined by an equilibrium relationship pH2 (ppm)=78,000×ê[(−58,900+13.1 T)/(1.987*T(° K))] around the inlet body of the inlet tube. ### Claim 4 (depends on 1) The system of claim 1, wherein: the inlet tube receives molten glass from a downcomer in the glass manufacturing system; the inlet tube outputs the molten glass to a forming vessel in the glass manufacturing system; and, the second seal prevents or mitigates the humid gas mix from being directed towards the forming vessel and a plurality of heating elements which emit heat around the forming vessel. ### Claim 5 (depends on 4) The system of claim 4, wherein the molten glass has a viscosity in range of 14,000 poise to 75,000 poise. ### Claim 6 (depends on 4) The system of claim 4, wherein the molten glass is non-alkaline molten glass or alkaline molten glass. ### Claim 7 A method for controlling an environment around an inlet tube in a glass manufacturing system, wherein the inlet tube comprises an inlet body, an input opening, and an output opening, said method comprising: providing an electrical heating unit encompassing at least a portion of the inlet tube and having a gas inlet unit and a gas outlet unit each passing therethrough; installing a first seal proximate the input opening and intermediate an exterior of the inlet body and the electrical heating unit; installing a second seal proximate the output opening and intermediate the exterior of the inlet body and the electrical heating unit; providing a refractory tower encompassing the electrical heating unit and having the gas inlet unit and the gas outlet unit each passing therethrough; and, providing a control system that directs a humid gas mixture into the gas inlet unit such that the humid gas mixture flows over the inlet body and exits the refractory tower and the electrical heating unit via the gas outlet unit. ### Claim 8 (depends on 7) The method of claim 7, wherein said inlet tube include a metal selected from platinum, platinum-containing metals including platinum-rhodium, platinum-iridium and combinations thereof, or refractory metals including palladium, rhenium, ruthenium, and osmium, or alloys thereof. ### Claim 9 (depends on 7) The method of claim 7, further comprising the step of controlling a level of hydrogen within the humid gas mixture to maintain a partial pressure at or greater than a level defined by an equilibrium relationship pH2 (ppm)=78,000×ê[(−58,900+13.1 T)/(1.987*T(° K))] around the inlet body of the inlet tube. ### Claim 10 (depends on 7) The method of claim 7, further comprising the steps of: receiving molten glass from a downcomer in the glass manufacturing system; outputting the molten glass to a forming vessel in the glass manufacturing system; and, mitigating the humid gas mix from being directed towards the forming vessel and a plurality of heating elements which emit heat around the forming vessel. ### Claim 11 (depends on 10) The method of claim 10, wherein the molten glass has a viscosity in range of 14,000 poise to 75,000 poise. ### Claim 12 (depends on 10) The method of claim 10, wherein the molten glass is non-alkaline molten glass or alkaline molten glass. ### Claim 13 A glass manufacturing system comprising: an inlet tube, a forming vessel, and a plurality of heating elements, wherein the inlet tube receives molten glass, the forming vessel receives molten glass from the inlet tube and forms a glass sheet, and the heating elements emit heat around the forming vessel; and a system for controlling an environment around the inlet tube which comprises an inlet body, an input opening, and an output opening, said system comprising: an electrical heating unit encompassing at least a portion of the inlet tube and having a gas inlet unit and a gas outlet unit each passing therethrough; a first seal proximate the input opening and intermediate an exterior of the inlet body and the electrical heating unit; a second seal proximate the output opening and intermediate the exterior of the inlet body and the electrical heating unit; a refractory tower encompassing the electrical heating unit and having the gas inlet unit and the gas outlet unit each passing therethrough; and, a control system that directs a humid gas mixture into the gas inlet unit such that the humid gas mixture flows over the inlet body and exits the refractory tower and the electrical heating unit via the gas outlet unit. ### Claim 14 (depends on 13) The glass manufacturing system of claim 13, wherein said inlet tube includes a metal selected from platinum, platinum-containing metals including platinum-rhodium, platinum-iridium and combinations thereof, or refractory metals including palladium, rhenium, ruthenium, and osmium, or alloys thereof. ### Claim 15 (depends on 13) The glass manufacturing system of claim 13, wherein the control system is configured to control a level of hydrogen within the humid gas mixture so that a partial pressure is maintained at or greater than a level defined by an equilibrium relationship pH2 (ppm)=78,000×ê[(−58,900+13.1 T)/(1.987*T(° K))] around the inlet body of the inlet tube. ### Claim 16 (depends on 13) The glass manufacturing system of claim 13, wherein the molten glass has a viscosity in range of 14,000 poise to 75,000 poise. ### Claim 17 (depends on 13) The glass manufacturing system of claim 13, wherein the molten glass is non-alkaline molten glass or alkaline molten glass.